Edit subtitles, one step at a time
Fix wrong words, subtitles that appear too early or late, or a line that disappears too soon. Open your subtitle file, review it against the recording, and save a corrected SRT or VTT.
Find a fix for your subtitle problem, or follow the six illustrated steps below.
1. How do I open a subtitle file?
Choose Open SRT / VTT / SBV and select one subtitle file, then click Load into editor. You can also paste subtitle text into the box before loading it. Each cue becomes a row with a start time, end time and caption text.
Selecting a file fills the text box; it does not load the editable rows yet. Check that the text appears, then load it. If the file cannot be read, save a UTF-8 copy and try again. Invalid timing or empty source cues must be fixed before import.
Check: You should see three editable rows when using the practice file.
Back to the editor2. How do I change subtitle text and timing?
Edit the Caption field to change the words. Edit Start and End to change when that cue appears and disappears. Your changes apply immediately to the editor; save a download to keep them after closing the tab.
Use times such as 00:00:03,600 or shorthand such as 3.6. End must be later than Start. The picture changes punctuation only to make an edit visible; use your recording to decide the correct wording.
Add entry creates a blank cue after the last entry. Give it text and valid times before exporting. Remove deletes that row. Keep an untouched source file so you can start again if needed.
Check: Read the edited words, then verify that Start is earlier than End.
Back to the editor3. How do I move all subtitles earlier or later?
Use Shift all times (seconds) when the whole subtitle track is consistently early or late. Enter an offset and click Apply shift once. A positive value moves every cue later; a negative value moves every cue earlier.
In this example, 0.5 moves cue 2 from 00:00:03,600 → 00:00:07,500 to 00:00:04,100 → 00:00:08,000. These are the practice file’s actual before-and-after times.
Each click applies the offset again. Check the result before clicking twice. Times below zero are clamped to zero; a large negative shift can make a cue end at its start and block export. Repair that cue or reload your original file. If timing drifts unevenly, review individual cues instead of applying one offset to everything.
Check: Replay the beginning and end of the recording after an overall shift.
Back to the editor4. How do I check subtitles against my recording?
Choose Open recording for review and select a local audio or video file. Click a cue’s number in the first column to start playback from that cue’s start time. If playback does not begin, press Play in the media controls.
Listen for names, numbers, missing words and the start of each phrase. The player lets you hear the recording; it does not automatically align captions, display an audio waveform or overlay the subtitle track. Check the exported file with your video in its destination player too.
Playback depends on the browser’s codec support. If the recording cannot play, you can still edit and export subtitles. The recording stays in this tab and is released when you clear the editor.
Check: Start from a cue number and confirm that you hear the expected phrase.
Back to the editor5. Why are the export buttons disabled?
Every cue needs text and valid times with End later than Start. If a cue fails that check, Copy SRT and both download buttons are disabled. Read the status message above the recording controls to find the cue that needs attention.
The example deliberately sets cue 1’s Start and End to zero. Restore its End to 00:00:03,600 to repair this practice cue. For your own file, use the correct time from the recording. If the message says a cue needs subtitle text, fill its Caption field or remove the unwanted row.
Check the message again after each repair: another invalid cue may still need attention. Valid overlapping cues keep their timing; overlap alone is not an export error.
Check: The status should say “Subtitles are ready for export.” and the download buttons should be enabled.
Back to the editor6. How do I save the edited subtitles?
Choose Download SRT or Download VTT, using the format your destination player or editor accepts. Both include your edited words and times. Copy SRT copies the subtitle syntax, including timecodes, rather than plain transcript text.
Reopen the downloaded file and check the first and last cues, the lines you edited and any shifted times. Then test it with the recording in the destination player. A successful download confirms that a file was created, not that the wording or synchronization is correct.
Download before closing or reloading the tab. There is no account project history or automatic cloud save. To remove timecodes instead, use SRT to Text.
Check: Confirm that the exported file contains your latest changes.
Back to the editorWhat is wrong with your subtitles?
Choose the issue that matches your file. Each answer links to the relevant illustrated step or the next tool you need.
How do I fix wrong names or words in automatic subtitles?
Open the SRT or VTT file, click Load into editor, and correct the affected Caption field. Check names, numbers and technical terms against the recording. If the words already appear at the right moment, leave Start and End unchanged.
Review other occurrences of the same name manually; there is no bulk find-and-replace in this editor. Download the corrected file when you finish. See the illustrated text-editing step.
My subtitles appear after the speech. How do I make them earlier?
For a consistent delay, enter a negative value in Shift all times (seconds). If every line appears half a second late, use -0.5 and click Apply shift once. Replay a line near the beginning and another near the end to check the result.
This is an example offset, not an automatic measurement. Use the amount your recording needs. If only one line is late, edit that cue instead. See how shifting works.
My subtitles appear before the speech. How do I delay them?
For a consistent early offset, enter a positive value in Shift all times (seconds). For example, use 0.5 to move all cues half a second later, then click Apply shift once. Both the start and end of each cue move by that amount.
Check the recording before shifting again: each click applies another offset. If your video has a different cut or introduction, confirm that the subtitle file matches that version first. View the before-and-after timing example.
How do I fix one subtitle that disappears too quickly?
Edit that row’s End time rather than shifting the whole file. Replay the phrase and choose an end that keeps the words visible for the intended speech. Check the next cue as well, so an extended line does not remain on screen over unrelated words.
If the line starts at the wrong moment, adjust its Start too. There is no automatic reading-speed or alignment adjustment. Use the recording review step, then check the exported subtitles in your destination player.
Why do my subtitles get further out of sync as the video plays?
A single offset moves every cue by the same amount. It cannot repair a mismatch that grows or changes after an edit. First check that the subtitle file belongs to the same version of the recording, including any cuts, added introduction or speed changes.
Compare cues near the beginning, middle and end. If a matching subtitle file is unavailable, review affected cue times individually or use a tool that supports timeline scaling or automatic alignment. This editor has neither feature. See the fields you can adjust manually.
How do I remove duplicate subtitles or add a missing line?
For a duplicate, compare both rows with the recording, then use Remove on the unwanted row. Keep repeated words when the speaker actually repeats them.
Add entry appends a blank cue after the last row. Supply its words and correct Start and End times. It does not insert a row in the middle or sort rows when you change their times.
For a missing line in the middle, save your current edits as SRT first. In a text editor, insert the missing cue in that saved file at the correct position, with its wording and valid timing. Reload the file here, review the cue order, and export again. The saved copy keeps your earlier edits. See how to save and reopen an edited file.
Can I correct subtitles downloaded from a YouTube video?
Yes, if you have an SRT or VTT file you are allowed to use. Load it here, review the text against your permitted local recording, and save the corrections. A YouTube URL alone is not a subtitle file for this editor.
To obtain an existing caption track first, use YouTube Transcript Download and select the intended caption language before saving SRT. That tool cannot create a missing caption track. Editing a downloaded file here does not update the captions on YouTube. Start with the import step.
Does downloading SRT add the subtitles to my MP4 video?
No. The download is a separate subtitle file; your video is unchanged. Load the SRT or VTT alongside the video in a player or video editor that supports that format, and check the result there.
If you need a new video with captions permanently visible, use a video editor that can render or burn them into the picture. InstaScript’s Subtitle Editor does not render videos, extract text from burned-in captions or generate subtitles from an MP4. For English speech without a subtitle file, start with Video to Text, then review the transcript and its timing.
More questions
Which subtitle formats can I edit?
Open one SRT, VTT or SBV file, or paste its text. Export SRT or VTT. SRT uses comma-separated milliseconds; WebVTT uses a WEBVTT header and period-separated milliseconds. SBV input uses comma-separated time ranges.
The editor works with cue text and timing. VTT style blocks, positioning settings and inline formatting tags are not retained. Use subtitles under 2 million characters and up to 10,000 cues. It does not merge or batch-edit files.
Are my subtitles or recording uploaded?
No. Local subtitle parsing, edits, playback and downloads happen in your browser. No account is needed. Another InstaScript transcription tab can send cues and a recording directly to this same-origin editor tab; that transfer is not placed in the URL or saved as a cloud project. See the privacy policy.
Can I edit subtitles in another language?
Yes. You supply the subtitle text; this editor does not run speech recognition or translate it. The English-only limit belongs to the separate speech transcription tools. If you want to enter a translation while keeping source timing, use the manual Subtitle Translator.
What if I only have a recording or plain text?
For an English recording, use Video to Text or Audio to Text first, review the transcript, and send valid timed cues to this editor or export SRT. If you only have plain text, TXT to SRT creates an estimated timing draft for manual review. This editor does not transcribe audio or perform automatic alignment.